Fluid-pressure-actuated tool.



9.11. GILMA-N'l- A FLUID PRESSURE CTUATEDhTOOL.

APPmoATIoN Hup un 19, 1909-.

'llatented May` 5, @91.4.

al. H H1 m@ www f 'enenen H. erm/Inner tirniniii'iroiii`T,l Naw-Haiaisnnn' AssIGNoR, BY mesita Assr'eNian'NTs, r9' si'JLL'ifvAnMAcHiNERY'coiurannj or Boeren, massacnn; sETTs, a coarona'rron orMassnenusnr'r's. f

rLUrD-PnEssURn-aewiimn Toon Y Speciication 'of Letters latent.. Patjlitdlg, Application mea may ia, 1909.. serial No. .496,91s.' t. 7

To all who/i 'ztmayconcerf/t: l

Beit' known that I, GEoRGE lH. GILMAN,

La citizen of the United States, residing at haGlar'emont, in thecountyof Sull-ivan and f State yot. New- Hampshire, have invented 'anImprovement in Fluid --Pressure Actuated Tools, .of which the -followingdescription,

` inconnectionwith the accompanying draw- `ings, is al' specification,likeletters on the drawingsrepresenting like parts. i

My inventionrelates to fluid pressureactuated tools andmore-particularly to the valve mechanism for'controlling thead-mi'ssion'of the motive'iiuid to and exhaustl from the cylinder. f-f l v Myinvention will be best understood by Y referencefto the followingdescription when taken in connection-with the accompanying illustration'of 'one specific embodiment thereof, while its 'scope will be more.par'- ticularly -pointed out/in' the appended claims.

v In the drawings: Figurel 1 is a central,

.l longitudinal section, partially brokenL away,

f of illustration 'bodiment. of my invention, the samecointaken'throiigh the cylinder and valve block, -of apressurefluidpercussive to'ol embodying onefforni; 'of myl invention; Fig. 2 i's asimilar view showing the valve and the pis'- ton hammerin a direrentrelation; and Fig. A 3 isa detail in sectional-plan on the-line3'-3inFi`g.2. Referring'tonthedrawings, foin-the sake I have there shownone emprising a'- pneumatic' hamjmer. 'd-IilL The Ala'tter hasthecylinderl, the forward portion of-whichis shown `broken away:vTheeyl-` inder -chamber 2 contains reciprocating blow against any `4,-Vwhich herein is `interposed between. the

which y'is adapted to 'deliver its suitable' receiving mem'- ber, such,for example, as the impact block Ihead offthe piston and' the drill orother y 'tool carried', tis-usual,V inthe foi-wardl endof the cylinder,but not herein shown.' l

The movements, ofthe-.piston are con` -trolledby a'controlling valve .5,.herein '1ny the i v form of a hollow cylindrical shell locateduinavalve chamber' at the rear of the cylinder chamber but inline .chamberbeingprovided .herein by "a twotherewith.- such .valve .13, of whichthere may be .rearward position .(see

l'walls of Athe .cylinder and .f cylinder chamber through 4.its rearvend such passage extendsfthroughm l pai'wtvalve blockpcomposed oftheforward `section 6 andthe rear'section 7. Both'sectionsfofthe valveblock are seated lwithin the walls ofa suitable casing 8 vwliiclipro-.-v

jects fromithehead .block 9,.therear1por- 55 tion of the" latter being.broken away. The.'

headvbloclris Providedwith afsupplyehaniber 10 for the motiveiiuid, towhich the l-atter is constantlyY admitted Vfronfiany suitable-J sourceof supply` throughthe supplyfpas- 60 sa e'11. I v

or. the admission of'fmotive fluid te; the

rear of the lcylinder chamber, .the lvalve chamber is yprovided with anannular vafl-,.1 mission .groove12, whichvhas constant ,come5'municatio'n with the supply chamberl() through the f'rearwardlyextending .pass.ages

suitable or desired number.y Wheniiif.its..l

chamber behind the admission .f

thereby. cutting olf the interiouo the vhalve and the rear of thecylinder chamber- ,from. the motive fluid. In' thesfoitvvard position of'7a the valve,-however 5.(see Fig; 1') the .interior of the' vvalve isopened fie'ely to the admission groove 12 so that-the motive fluid.-'lows -freely to .the interior of the valve and. thence to the rear ofthe cylinder chamber teldrive so ,the piston forwar' The, forward ,endof the cylinder .is supplied with motive vluidwhlen there] ve `is.atfits rearwardposition". (see Fig. 2) by f means of the returnpressure.. passage 14,55

which extends. longitudinally through v-the.

opens,y into .the theportflgffAt nIn the, rearvs'a-frdv to giveasuicieiitly free admission o ffmotYQ; g.

Huid. to the-groove 147 byway. of vthe valve *ice ser providedany v-Fig. `2) ,the-real Bild 7e of the valve enters that portion yOfthievnlvecove 12,\

thevalve block. section- 6. and terminatesfini` 9a? vl'a lateral .portlopening ,into an" annular fvalve. block L groove 17. position of thevalvethe groovel.- is'con- .nected with they motive fluid by `means of Agi-153g@ groove 18 to return the piston hammer. From the groove 17 themotive uid passes through the port 16, passageql-ly and port 15 to theforward end ofthe cylinder.

To exhaust the motive iuid from the rear of the cylinder chamber,lateral exhaust passages A2O are provided in the valve block, whichpassages open into the valve chamber at the annular 'groove orenlargement 21, which latter,l forms an annular chamber to receive thecircumferential enlargement near the yforward end of the valve. Theselateral exhaust ports communicate with the longitudinal exhaust ports 23extending through the valve block, the longitudinal ports at their rearcommunicating with the permanently open exhaust ports 24 formed in thehead block. When the valve is in its rearward position (Fig. 2), theprolonged portion 25 of the valve which extends beyond thecircumferential enlargement 22, lifts from its seat sufficiently'` toopen the rear of the cylinder chamber to the bottom of the valve blockchamber 21, thus placing the rear of the cylinder chamber incommunication with the exhaust port-s .20. As shown in the gdrawings,the ports 20are only partially uncovered by the valve when in thisposition, but'such ports may be, and preferably are, of an elongatedcross-section, as shown in dotted lines in Fig. 2, so that, by suitablyproportioning such ports, the exhaust from the rear of the cylinderchamber" may be made as free or restricted as desired.

To exhaust mot-ive Huid from the forward 4end of the cylinder chamber,the latter is provided with one or more (herein two) exhaust ports 26,adapted to be uncovered by the piston before the completion of the rearward movement thereof, such ports being connected with the longitudinalexhaust passages 27 and thereby with the atmosphere through thepermanently open exhaust passages 23 and 24. In addition to this, theforward end of the cylinder is maintained open for the exhaust of motivefluid during v the forward movement of the piston, and after the closureof the exhaust ports 2G, through the return port 14, the latter beingthere connected through the valve 'chamber when the valve is positionedas shown in 4ig. 1, with the valve groover 18, the exhaust chamber 21and the exhaust ports 20.

Referring now more particularly to the provlsion for moving the valve toreverse the piston, the rear end portion 28 of the valve is of slightly`reduced diameter, having a sliding fit in the corresponding reducedportion of the valve chamber beyond the admission groove 12. This forms-a. small circumferential shoulder 29 which constitutes a small pressurearea constantly exposed to the motive fluid in the admission groove 12.On the other hand, the lower ace of the noeaa circumferentialenlargement 22 constitutes' an. opposing differential pressure area ofrelatively greater proportions. When the valve is in its forwardposition (shown in Fig. 1) the valve is maintained in such positionduring the forward movement of the piston by the pressure on the smallarea 29 augmented by the pressure on the rear end area of the valve,there being then no substantial pressure against the larger o posingkpressure area in the lower end of t e chamber 21. To insure the absenceof substantial pressure against this larger area there may be, andpreferably are, provided one or more release ports 30 (herein two innumber) connecting the lower end .of such chamber with theexhaust-passage or passages 23, these serving to exhaust any pressurefluid trapped in ythe bottom of said chamber or entering thereinto byleakage from the cylinder chamber. Means are provided, however,l wherebythe piston during its forward movement is adapted to admit pressurefluid to the large opposing pressure area to lift the valve to theposition shown in Fig. 2 and thereby reverse its own movement. To thisend a' port 31 is provided which is adapted to be uncovered by thepiston to the motive fluid at the rear thereof, such port conducting themotive Huid through the rearwardly extending passage 32 to the bottom cfthe chamber 2l and against the large opposing pressure area.

formed on the under face of the-circumferential enlargement 22. The port31 may bc located at any suitable point, but preferably so that it-isuncovered just prior to the striking of the blow. Then uncovered, thepressure upon the large opposing differential area exceeds that on thesmall pressure area 29 and the end area of the valve, and quicklyreverses the valve, lifting tothe position shown in Fig. 2. As abovedescribed, this admits motive Huid to the forward end of the cylinderchamber and opens the rear end thereof to the exhaust, so that thepiston, having delivered its Iblow, moves back on its return stroke.

The piston carries projecting from its rear end a plug portion 33 which,in the illustrated embodiment of my invention, is of lesser diameterthan the piston itself. This plug portion is adapted to project out ofand beyond the piston or cylinder chamber inthe rearward position of thevalve, and

Vthrough an aperture 34 in t-he valve block in which it preferably hasav sliding lit, and which constitutes a port leading from the valvechamber to the piston chamber. The valve having been reversed, thepiston during its return movement expels the motive fluid at the rear ofthe cylinder chamber through the exhaust chamber 21 and the exhaustports 20. During this movement of the piston, the slight pressuremaintained by the'disciharguig xhaust fluid inthe exhaust i chamber '21and against the large opposing pressure area at ythe bottom of thecircumferential enlargement 22 predominates over the constant pressureacting against the small pressure area 29, andis suiiicient to maintainthe valve reversed in the position shown in Fig. 2, to which position,as above described, it has been thrown by motive iuidadmitted by theypiston through the passagei Thisfcondition continues 'and the valvesh'eld reversed by theaction of alle'. exhaust pressure preferably afterthe .iiilg portioiientersthe aperture 34 and soy fing as there is any`substantialpressureex- .valve block ,section Gfby k.reason oftheclosureof the aperture 34 by the plug'33. This bringsA .theI pistontorest and vprevents it from striking the valve' block should the -valvefail torreverse.' About the saine time,

however, thereinainant motive fluid, having been substantiallyexpelled,the lpressurejof 'the discharging exhaust against the larger Vpressurearea of the vvalve is reduced to such' a low point that the v Ive isquickly re ,v

versedby the superior pressure-against the small pressure area ,29. Asabove described,

this admitslive pressureuid from the adward.- At the same time theforward end of -tlie piston -chamber which has been previously opened.tothe exhaust by the uncovering of the exhaust ports 26, is also openedtothe exhaust .through the valve 'chamber by way of the return port 14,this condition holding until the valve is again ref versed.' The valvewhen reversed, is held securely in its forward position, since therelease ports 30 relieve tlielarger pressure. area ofthe pressure of anyaccumulated motive fluid.

'IWhile the length of the projecting plug portion 33 might be reduced soas not to projecty within the, valve in the rearinost position'j'of thepiston, herein, for the sake of reducing-.the clearancey Within thevalve cliiniber, it is somewhatprolonged, as shown -in the drawings, sothat it not only passes tlirou hand closes the port-'like aperture 34,but a' so enters partl way into vthe valve itself. @The interior'vdiameter y of the valve,

lidwever. .is madeslightlygreater'than the i I claim is:

exteriordianieter voffthe plug, so that a small clearance spaceremainsbetween thevalveandl the enteringportion of the-piug.""' This permitsythe motive fluidtrapped, w1th` its length and separated from each otherby @hmmm when 'the ping eaters the visive,

Itwill be observed located in a separate chamber behindvthe missiongroove v12, driving the piston for- Such escape, moreover, maybefacilitated,

if desired, by any suitable formation of the plug, such, for. example,as the provision of one o r more longitudinal grooves 35 cut part way onthe surface of the plug.

The described form of valve being very near the -close of the rearwardpiston movedelicatelybalanced, acts quickly to reversev ment 'so thatvery high'speed and a very' powerful blow can be @secured through itsemployment. Moreover, theclearance in the cylinder and valve chamberbeing reduced'to It may be. observed that the pressure exa minimunn avery high efficiency can be obtained. t '9 erted by the escaping exhaustagainst the larger pressure ar'ea can be' varied, and the action of thevalve thereby varied within wide limits, through increasing -ordecreasjing the available'cross-sectional area of the l'exln'iust ports'opened to the exhaust chamber 21'on the vbackward movement ofV thevalve by the circumferential enlargement 22. That is to say, .byincreasing the area or the number 'ofthe exhaust ports' 20, or by fincreasing the extent of exhaust port opening, when the valve is movedto the position l shown in Fig. 2, thevalve-.lifting pressure,

due to the exhaust, is diminished. lConverSely, by decreasing'the areaor number of such' `ports tlievalve-lifting pressure is increased andprolonged.

piston chamber and between the latter and 1 the headblocleit is notnecessary for the i operation of the tool that any part of the pistonenter the valve. Herein the plug 33 carried by the piston is caused toenter the valve chamber to reduce the clearance therein, b ut such isnot essential; The clearance within the valve chamber might be reducedby making the valve solid except for a cenL tral axial admission passagethrough the same, or .with a valve proportioned as shown, a stationaryplug might be' employed 'projecting forwardly within the valve from thethat the valve, being A foo llO

forni' and relative arrangements of Vthe parts and the application oruse herein niad'e of l. A pressure fluid percussive tool 'having fapiston hamnieiga valve having two 'pres'- sure areas at differentpoints, respectively, in

a cylindrical surface, means fitting said cy lindricalsfurlacezin oneposition, o f the valere,

`tlie invention, without departing from the f means to cause said valveto loe moved into another position bv motive fluid acting.,r against oneof said pressure areas, and means to cause thc valve to be held, when somoved, by the pressure of' the discharged exliaust actingl against bothof' said areas.

2. A. pressure fluid percussive tool having a piston hammer, an annularvalve, means to cause said valve to he moved in opposite directions bypressure tluid, means for closing' the rear end ot' said valve in itsrearmost position, a release port and means for causing said valve to heheld in its rearniost position h v the pressure of' the exhaust fluidescaping' from the interior of said valve radially outward across theforward end of the valve to said release port.

-l. A pressure fluid percussive tool having;

a piston hammer provided with a plug,` portion, a piston chamber, anannular valve, a valve chamber located at. the rear of the c vlinderchamber, an axially arranged port connecting' the valve chamber andpiston chamber into which port the plug portion is adapted to enter,means 'for admitting' pressure fluid to the rear end of the plug poi'-tion and to the rear end of' the piston chamber through the hollowinterior of' the valve, and means for exhausting pressure fluid from therear of the piston about the forward end of the valve.

4. A pressure fluid percussive tool having a piston hammer provided witha rearwardlv projecting' plug` portion, an annular valve. said toolhaving means including' exhaust ports adjacent the forward end of thcvalve .for releasing' the exhaust fluid from the rear end of. theevlinder chamber radiall)1 outward about and across the forward end ofthe valve. the interior of the valve .heine formedV to permit the escapeot eX- haust fluid radiall)7 outward to said exhaust ports trom theinterior of' the valve.

5. .l pressure fluid ptn'cussive tool having' a cjvlinder chandler, apiston hammer provided with :i rarwardly projecting plug,r portion, avalve located behind said cylinder chamber. a port. connecting the valvechainber and cylinder chamber, through which port said projectiirnyplug' portiony passes on rearward movement' 01' the piston. said plug'portion beine' also extended to enter the valve` the 4interior of. saidvalve and said plut' portion beine; formed to permit the es- -ape ofexhaust fluid 'from the rear inner end of the valve about the forwardend thereof` while also formed closel'v to fit lsaid. port to provide'o'r theformation of a fluid cushion at the rear of'the. pist-on.

(l. A pressure fluid pereussive tool having' a piston han'nner and anannular valve at the rear thereof: a projecting plug; portion of thehammer adapted to enter the valve and torm- .ing with -said valve apassage permittine' the Yescape oi exhaust motive lluul from one 'wardacross one end of the valve to said reend thereof to the other; means tomove said valve in one direction b v constantly acting.r pressure'against an area thereof; means tc move said 'alve in the oppositedirection b5 pressure intermittentl)v admitted to a la rg'ezpressurearea thereof; and means to hold the` .valve in said last named positionby the action of the escaping exhaust.

, 7. A. pressure fluid'percussive tool haviln.r a piston hannner and anannular valve, means for closing the rear end of said valve in itsrearmost position, means including an exhaust port for releasing theexhaust fluid from the interior of' said valve radially outlease portthereby to hold said valve in 8o position :tp permit such release of theexhaust fluid and means to move said vali l.- to a l'eversefvpositipnsolei)v by constantly acting' ressme fluid 'acting' against a pressurearea of the valve.

S. A pressure fluid percussive tool having a piston hammer. a pistonchamber, an annular controlling` valve open at both ends loated at therear of, and in line with the piston chamber. said valve heiliginteriorly open for the passage of fluid therethrough from one endthereof to the other, means for admitting' live pressure fluid throughthe said valve to 'drive' said piston forward, and meansI for holding'the valve in one position bv motive fluid and in the opposite position bv exhaust fluid.

9. pressure fluid percussive tool having a piston chamber. an-annularvalve which 100 communicatesl interiorlv at one end with the pistonchamber. an admission space at the opposite end ol 'the valve` anexhaust space exteriorly of the valve at' its first mentioned end` saidvalve when iii one position con- 105 'neeting the piston chan'iber withthe admission space about tht` end ot' the valve and through its hollowinterior. and when in the reverse position connectingr the pistonchamber with the exhaust space about the oppo- 119 site end of thev'alve. a pressure area at the admission end of' the valve being'constantly exposed to motive fluid and a larger pressure area al theexhaust end of' the valvc exposed to the exhaust fluid and servingr tohold the -valve open during exhaust.

itl. A pressure fluid percussive tool having' a piston chamber, anannular valve which communicates interiorlv at one end with the pistonchamber. an admission space 12u at the tipposite end of the valve. anexhaust space exteriorlv ot the valve at its til-st mentionedend. saidvalve when in one position connecting ihf1 piston chamber with theadmission space about the end of the valve and through its hollowinterior. and when in the reverse po,-iio:^= connecting' the pistonchain-- 'tier with the exhaust space about the oppi- -ite end nl' shevalve. a pressure area at Ilzadmission end ol the valve. beinurconstantly so exposed to niotivetluid anda larger pressurearea atth'eexhaust end of the valve exposed to` the exhaust fluidi-and serving tohold the valveopenyduringexhaust, a pis- 5 ton' and a part carried bythe end of the -piston'aclapted to .enter the valve on movement' of thelistenin one direction and substantially fill the interiorthereof.'5.v ll 11. A.' pressure fluid percussive tool havo i'tion, 'a pistonchamber,an annular'valve, valve chamber located at the rear ofl the adapted toenter and have ay slidingfit, means for .admitting pressure lluid'to therear end of. the pist-on" chamber through the hollow interior of 'thevalve, and means for` eX- haustiiig' pressure-fluid from the rear of thepiston about. the Jforward end of the valve.

' -12. Apressure fluid percussive tool having a cylinder chamber, apiston hammer .providedwith a rearwardly projecting plug ;portion, a4valve located behind said cylin-' der chamber, a port. connect-ing thevalve` chamber and c vlinder chamber, through which 'port saidprojecting plug portion passes on rearward mov-ement of the piston, i0the interior of said valvel and said plug portion being' formedt-o'permit the escape 4of exhaust fluid from the rear inner end oftheLvalve about theforward end thereof, while also formed closely to litsaid port-'to provide for the formation of a fluid cushion `at the rearof the piston.

,1%. A pressure fluid percussive tool hav-v ing a piston hammer providedwith 'a plug portion,ian annular v-alve at the rear of the 40.' pistonhammer@ said .toolhaving a piston chamber and a port formingacommunication between the pistonA chamber and the `interior vof thevalve, into' which port the plug portion is adapted to entei-'andclosely fit; means to move said valve -in one direction by constantlyact-ing pressure against an area thereof; means to move said valve inthe opposite direction b v pressure lintermittently admitted to a largerpressure area thereof: and means to hold the valve in the'l last namedposition bv the action of the escapingA exhaust. I

1l; A pressurefluid percussive tool having a piston hammer, an annularvalve having a pressure area, a pistou chamber having communication withthe interior of the valve, means to move the valve ina directionopposite to the piston 'by motive fluid 'passing through the valve intothe piston chamber and thence to said pressure area of` the valve, andmeans to hold the valve, when so moved. by the pressure of theexhausting fluid flowing across and acting against said pressure area. l5,5 .151;A pressnreuid percussive tool havng a piston hammer providedwith a plug`4 ft'zyliiideiv chamber, an axially arranged portllconnecting thevalve chamber and x 5 chamber into which porttheplugrtionis vsure .area at. the exhaust end 'of tlie `valvevterio'r, andwhen in the reverse posit-ion ooi` nectingthe' piston chamber with theexhaust space about the opposite end of the valve,

a pressure area at the admission end of the valvebeing constantlyexposed tomotive fluid and a larger pressure area at the eX- haust'endofthe valve exposed` to the lexhaustflud and serving to hold the valve`ropen ,during the exhaust. l Y 85 16. A pressure fluid percussivetoolhaving `a' piston chamber, an vannular valvel which communicatesinteriorly lat one'eiidv L with the piston chamber, an admissio'irspaceat the opposite end of the valve, 'an exhaust space exteriorly'of thevalve at its opposite end, said -valve'ivhen in one position 'con-Vnecting the piston chamber with the admis' sion space aboutl 4the endofthe valve'a-nd through its hollow interior, and when in the g reverseposition connecting thepi'ston cham-1y ber with the exhaust space aboutthe vopposite. end of the valve, a pressure-area atthe" admission end ofthe valve being constantly 1 exposed to motive fluid and a largerprese'xposed tothe exhaust vfluid and serving to' hold .the valve openduring exhaust, and a piston hammer arranged to reciprocate withinsaid'piston chamber.

17. Apressure fluid percussive tool -hav-Y ing a piston chamber, anannular valve which. communicates inteiiorly at its for- 'Ward endwitlithe piston chambery4 an admission space constantly lopen to motive"11o fluid at y'the opposite `end of-the valve, 'an exhaust spaceexteriorly of the valve at forward end, said -valve wlien'in oneposition connecting t-h'e piston cliamberwith theadmission spa-ce aboutthe forward end of'115" the valve and through its hollow interior, andwhen in the reverse position connecting they piston chamber with theexhaust space about. thel opposite end of the valve, a pressurea'i'ea attheadmission end of the'valve 120' being constantly exposed to mot-ivefluid and a larger pressure area at the-exhaust end of the .valveexposed tothe exhaust fluid and serving to hold the valve openduring'exciprfocate within vsaid piston chamber.

158. A' pressure.iluidpercussive tool having'- a cylinder chamber,piston hammer y provided with afrearwardly projecting plug haust. and apils on hammer arranged to re' 125 ,.portonand a hollow valve-.locatedbehindqgo ibi los

said cylinder' chamber, :i port connecting the In testimony whereof, Ihave signed my fvalve chamber e and cylinder chamber, name to thisspecification, in the presence of 10 through which port said projectingplug two subscribing Witnesses.

portion passes 'into said valve on rearward ,T movement of the piston,said plug portion GEORGE GILMB' beingformed closely to tsaid port topro- Witnesses: K

vide for the formaion of a Huid cushion at E. J. BRUOHARD,

the rear of the piston. S. T. CHANDLER.

